THE UPTAKE OF LOCALLY APPLIED [6:7-3H] OESTRONE BY THE VAGINA OF THE OVARIECTOMIZED MOUSE

Abstract

SUMMARY Locally applied [6:7-3H]oestrone was rapidly taken up by the vagina. The hormone content of the tissue reached a peak 1 min. after application, and thereafter dropped rapidly to a level of 20–30% of the administered dose at 27 min., and more slowly to a level of 6% at 16 hr. The hormone content of the lumen decreased rapidly to near zero at the end of 27 min. Simultaneous application of dimethylstilboestrol (DMS) had little effect on tissue levels at 1 min., but significantly reduced the fraction retained for longer periods. Progesterone was without effect. It is suggested that, after its rapid passage into the vagina, a small proportion of the hormone is bound at the site of action, where it is retained for some hours. Any unbound hormone is lost to the general circulation within 30 min. The results are discussed in relation to the mode of action of oestrogens and anti-oestrogens.